I have a bigquery table. Sample data in json format is

[{"cust_id": 12345,
"Seq_column": [1,2,3,4,5]}] 

When i fetch the data using pyspark and save it back to bigquery table, the structure of column “seq_column” is getting changed

[{"cust_id": 12345,
"Seq_column": [{"element":1},{"element":2},{"element":3},{"element":4},{"element":5}
}]}] 

How can i maintain the structure of that column as original?
I tried array type function of pyspark. Closer solution i got is converting it to stringtype before saving. But that is not correct. Is there any other way?